summaryrefslogtreecommitdiff
path: root/src/cpu/samsung/exynos5420/spi.c
diff options
context:
space:
mode:
authorGabe Black <gabeblack@google.com>2013-05-16 05:45:57 -0700
committerStefan Reinauer <stefan.reinauer@coreboot.org>2013-07-10 20:08:53 +0200
commit607c0b6d63f88c84661582800f2ee9a49325fcdb (patch)
tree9b26c0530ee09ef661610fb1faef2a1813e3da6c /src/cpu/samsung/exynos5420/spi.c
parentdc006c1db4fa3606d657c78cc87dc13d056e970d (diff)
pit: Create an exynos5420 directory which is nearly a copy of exynos5250.
This change creates an exynos5420 directory with code that will eventually implement support for the exynos5420 cpu from Samsung. Currently it's a copy of the exynos5250 directory with the name changed. There are going to be some problems where headers in src/cpu/samsung/exynos-common include headers in the exynos5250 directory directly. Change-Id: Ia8d7244310d32499238bbc171c0c668ec48178e1 Signed-off-by: Gabe Black <gabeblack@chromium.org> Reviewed-on: http://review.coreboot.org/3644 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/cpu/samsung/exynos5420/spi.c')
-rw-r--r--src/cpu/samsung/exynos5420/spi.c222
1 files changed, 222 insertions, 0 deletions
diff --git a/src/cpu/samsung/exynos5420/spi.c b/src/cpu/samsung/exynos5420/spi.c
new file mode 100644
index 0000000000..503cee90ee
--- /dev/null
+++ b/src/cpu/samsung/exynos5420/spi.c
@@ -0,0 +1,222 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2011 Samsung Electronics
+ * Copyright 2013 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <console/console.h>
+#include <arch/io.h>
+#include <stdlib.h>
+#include <assert.h>
+#include "gpio.h"
+#include "clk.h"
+#include "spi.h"
+
+#define OM_STAT (0x1f << 1)
+#define EXYNOS_BASE_SPI1 ((void *)0x12d30000)
+
+#if defined(CONFIG_DEBUG_SPI) && CONFIG_DEBUG_SPI
+# define DEBUG_SPI(x,...) printk(BIOS_DEBUG, "EXYNOS_SPI: " x)
+#else
+# define DEBUG_SPI(x,...)
+#endif
+
+static void exynos_spi_rx_tx(struct exynos_spi *regs, int todo,
+ void *dinp, void const *doutp, int i)
+{
+ int rx_lvl, tx_lvl;
+ unsigned int *rxp = (unsigned int *)(dinp + (i * (32 * 1024)));
+ unsigned int out_bytes, in_bytes;
+
+ // TODO In currrent implementation, every read/write must be aligned to
+ // 4 bytes, otherwise you may get timeout or other unexpected results.
+ ASSERT(todo % 4 == 0);
+
+ out_bytes = in_bytes = todo;
+ setbits_le32(&regs->ch_cfg, SPI_CH_RST);
+ clrbits_le32(&regs->ch_cfg, SPI_CH_RST);
+ writel(((todo * 8) / 32) | SPI_PACKET_CNT_EN, &regs->pkt_cnt);
+
+ while (in_bytes) {
+ uint32_t spi_sts;
+ int temp;
+
+ spi_sts = readl(&regs->spi_sts);
+ rx_lvl = ((spi_sts >> 15) & 0x7f);
+ tx_lvl = ((spi_sts >> 6) & 0x7f);
+ while (tx_lvl < 32 && out_bytes) {
+ // TODO The "writing" (tx) is not supported now; that's
+ // why we write garbage to keep driving FIFO clock.
+ temp = 0xffffffff;
+ writel(temp, &regs->tx_data);
+ out_bytes -= 4;
+ tx_lvl += 4;
+ }
+ while (rx_lvl >= 4 && in_bytes) {
+ temp = readl(&regs->rx_data);
+ if (rxp)
+ *rxp++ = temp;
+ in_bytes -= 4;
+ rx_lvl -= 4;
+ }
+ }
+}
+
+/* set up SPI channel */
+int exynos_spi_open(struct exynos_spi *regs)
+{
+ /* set the spi1 GPIO */
+
+ /* set pktcnt and enable it */
+ writel(4 | SPI_PACKET_CNT_EN, &regs->pkt_cnt);
+ /* set FB_CLK_SEL */
+ writel(SPI_FB_DELAY_180, &regs->fb_clk);
+ /* set CH_WIDTH and BUS_WIDTH as word */
+ setbits_le32(&regs->mode_cfg,
+ SPI_MODE_CH_WIDTH_WORD | SPI_MODE_BUS_WIDTH_WORD);
+ clrbits_le32(&regs->ch_cfg, SPI_CH_CPOL_L); /* CPOL: active high */
+
+ /* clear rx and tx channel if set priveously */
+ clrbits_le32(&regs->ch_cfg, SPI_RX_CH_ON | SPI_TX_CH_ON);
+
+ setbits_le32(&regs->swap_cfg,
+ SPI_RX_SWAP_EN | SPI_RX_BYTE_SWAP | SPI_RX_HWORD_SWAP);
+
+ /* do a soft reset */
+ setbits_le32(&regs->ch_cfg, SPI_CH_RST);
+ clrbits_le32(&regs->ch_cfg, SPI_CH_RST);
+
+ /* now set rx and tx channel ON */
+ setbits_le32(&regs->ch_cfg, SPI_RX_CH_ON | SPI_TX_CH_ON | SPI_CH_HS_EN);
+ clrbits_le32(&regs->cs_reg, SPI_SLAVE_SIG_INACT); /* CS low */
+ return 0;
+}
+
+int exynos_spi_read(struct exynos_spi *regs, void *dest, u32 len, u32 off)
+{
+ int upto, todo;
+ int i;
+ /* Send read instruction (0x3h) followed by a 24 bit addr */
+ writel((SF_READ_DATA_CMD << 24) | off, &regs->tx_data);
+
+ /* waiting for TX done */
+ while (!(readl(&regs->spi_sts) & SPI_ST_TX_DONE));
+
+ for (upto = 0, i = 0; upto < len; upto += todo, i++) {
+ todo = MIN(len - upto, (1 << 15));
+ exynos_spi_rx_tx(regs, todo, dest, (void *)(off), i);
+ }
+
+ setbits_le32(&regs->cs_reg, SPI_SLAVE_SIG_INACT);/* make the CS high */
+
+ /*
+ * Let put controller mode to BYTE as
+ * SPI driver does not support WORD mode yet
+ */
+ clrbits_le32(&regs->mode_cfg,
+ SPI_MODE_CH_WIDTH_WORD | SPI_MODE_BUS_WIDTH_WORD);
+ writel(0, &regs->swap_cfg);
+
+ return len;
+}
+
+int exynos_spi_close(struct exynos_spi *regs)
+{
+ /*
+ * Flush spi tx, rx fifos and reset the SPI controller
+ * and clear rx/tx channel
+ */
+ clrsetbits_le32(&regs->ch_cfg, SPI_CH_HS_EN, SPI_CH_RST);
+ clrbits_le32(&regs->ch_cfg, SPI_CH_RST);
+ clrbits_le32(&regs->ch_cfg, SPI_TX_CH_ON | SPI_RX_CH_ON);
+ return 0;
+}
+
+// SPI as CBFS media.
+struct exynos_spi_media {
+ struct exynos_spi *regs;
+ struct cbfs_simple_buffer buffer;
+};
+
+static int exynos_spi_cbfs_open(struct cbfs_media *media) {
+ struct exynos_spi_media *spi = (struct exynos_spi_media*)media->context;
+ DEBUG_SPI("exynos_spi_cbfs_open\n");
+ return exynos_spi_open(spi->regs);
+}
+
+static int exynos_spi_cbfs_close(struct cbfs_media *media) {
+ struct exynos_spi_media *spi = (struct exynos_spi_media*)media->context;
+ DEBUG_SPI("exynos_spi_cbfs_close\n");
+ return exynos_spi_close(spi->regs);
+}
+
+static size_t exynos_spi_cbfs_read(struct cbfs_media *media, void *dest,
+ size_t offset, size_t count) {
+ struct exynos_spi_media *spi = (struct exynos_spi_media*)media->context;
+ int bytes;
+ DEBUG_SPI("exynos_spi_cbfs_read(%u)\n", count);
+ bytes = exynos_spi_read(spi->regs, dest, count, offset);
+ // Flush and re-open the device.
+ exynos_spi_close(spi->regs);
+ exynos_spi_open(spi->regs);
+ return bytes;
+}
+
+static void *exynos_spi_cbfs_map(struct cbfs_media *media, size_t offset,
+ size_t count) {
+ struct exynos_spi_media *spi = (struct exynos_spi_media*)media->context;
+ DEBUG_SPI("exynos_spi_cbfs_map\n");
+ // See exynos_spi_rx_tx for I/O alignment limitation.
+ if (count % 4)
+ count += 4 - (count % 4);
+ return cbfs_simple_buffer_map(&spi->buffer, media, offset, count);
+}
+
+static void *exynos_spi_cbfs_unmap(struct cbfs_media *media,
+ const void *address) {
+ struct exynos_spi_media *spi = (struct exynos_spi_media*)media->context;
+ DEBUG_SPI("exynos_spi_cbfs_unmap\n");
+ return cbfs_simple_buffer_unmap(&spi->buffer, address);
+}
+
+int initialize_exynos_spi_cbfs_media(struct cbfs_media *media,
+ void *buffer_address,
+ size_t buffer_size) {
+ // TODO Replace static variable to support multiple streams.
+ static struct exynos_spi_media context;
+ DEBUG_SPI("initialize_exynos_spi_cbfs_media\n");
+
+ context.regs = EXYNOS_BASE_SPI1;
+ context.buffer.allocated = context.buffer.last_allocate = 0;
+ context.buffer.buffer = buffer_address;
+ context.buffer.size = buffer_size;
+ media->context = (void*)&context;
+ media->open = exynos_spi_cbfs_open;
+ media->close = exynos_spi_cbfs_close;
+ media->read = exynos_spi_cbfs_read;
+ media->map = exynos_spi_cbfs_map;
+ media->unmap = exynos_spi_cbfs_unmap;
+
+ return 0;
+}
+
+int init_default_cbfs_media(struct cbfs_media *media) {
+ return initialize_exynos_spi_cbfs_media(
+ media,
+ (void*)CONFIG_CBFS_CACHE_ADDRESS,
+ CONFIG_CBFS_CACHE_SIZE);
+}